tag:theconversation.com,2011:/es/topics/pacemaker-6177/articlesPacemaker – The Conversation2024-03-15T12:11:36Ztag:theconversation.com,2011:article/2243502024-03-15T12:11:36Z2024-03-15T12:11:36ZPacemaker powered by light eliminates need for batteries and allows the heart to function more naturally − new research<figure><img src="https://images.theconversation.com/files/580746/original/file-20240308-16-3gcx17.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2000%2C1500&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Scientists have designed a solar panel-like pacemaker that can precisely control heartbeats.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/female-silhouett-and-heart-with-pacemaker-royalty-free-image/1490726996">Eugene Mymrin/Moment via Getty Images</a></span></figcaption></figure><p>By harnessing light, my colleagues <a href="https://scholar.google.com.sg/citations?user=hO6bRlwAAAAJ&hl=en">and I</a> designed a wireless, ultrathin pacemaker that operates like a solar panel. This design not only eliminates the need for batteries but also minimizes disruptions to the heart’s natural function by molding to its contours. Our research, recently <a href="https://doi.org/10.1038/s41586-024-07016-9">published in the journal Nature</a>, offers a new approach to treatments that require electrical stimulation, such as heart pacing.</p>
<p><a href="https://theconversation.com/how-do-pacemakers-and-defibrillators-work-a-cardiologist-explains-how-they-interact-with-the-electrical-system-of-the-heart-217429">Pacemakers are medical devices</a> implanted in the body to regulate heart rhythms. They’re composed of electronic circuits with batteries and leads anchored to the heart muscle to stimulate it. However, leads can fail and damage tissue. The location of the leads can’t be changed once they’re implanted, limiting access to different heart regions. Because pacemakers use rigid, metallic electrodes, they may also damage tissue when <a href="https://www.nhlbi.nih.gov/health/heart-surgery/during">restarting the heart after surgery</a> or <a href="https://www.mayoclinic.org/diseases-conditions/heart-arrhythmia/symptoms-causes/syc-20350668">regulating arrhythmia</a>.</p>
<p>Our team envisioned a leadless and more flexible pacemaker that could precisely stimulate multiple areas of the heart. So we designed a device that <a href="https://doi.org/10.1038/s41586-024-07016-9">transforms light into bioelectricity</a>, or heart cell-generated electrical signals. Thinner than a human hair, our pacemaker is made of an optic fiber and silicon membrane that the <a href="https://tianlab.uchicago.edu/">Tian lab</a> and colleagues at the University of Chicago <a href="https://pme.uchicago.edu/">Pritzker School of Molecular Engineering</a> have spent years developing. </p>
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<figcaption><span class="caption">Like solar panels, this pacemaker is powered by light.</span></figcaption>
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<p>Unlike <a href="https://www.energy.gov/eere/solar/solar-photovoltaic-cell-basics">conventional solar cells</a> that are usually designed to collect as much energy as possible, we tweaked our device to generate electricity only at points where light strikes so it can precisely regulate heartbeats. We did this by using a layer of very small pores that can trap light and electrical current. Only cardiac muscles exposed to light-activated pores are stimulated.</p>
<p>Because our device is so small and light, it can be implanted without opening the chest. We were able to <a href="https://doi.org/10.1038/s41586-024-07016-9">successfully implant it</a> in the hearts of rodents and an adult pig, pacing the beats of different heart muscles. Because <a href="https://theconversation.com/organs-from-genetically-engineered-pigs-may-help-shorten-the-transplant-wait-list-175893">pig hearts</a> are anatomically similar to human hearts, this accomplishment shows our device’s potential to translate to people.</p>
<h2>Why it matters</h2>
<p>Heart disease is the <a href="https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death">leading cause of death around the world</a>. Annually, <a href="https://www.nhlbi.nih.gov/health/heart-surgery">over 2 million people</a> undergo open-heart surgery to treat heart problems, including to <a href="https://theconversation.com/how-do-pacemakers-and-defibrillators-work-a-cardiologist-explains-how-they-interact-with-the-electrical-system-of-the-heart-217429">implant devices</a> that regulate heart rhythms and prevent heart attacks.</p>
<p>Our ultralight device gently conforms to the surface of the heart, enabling less invasive stimulation and improved pacing and synchronized contraction. To reduce postoperative trauma and recovery time, our device can be implanted with a minimally invasive technique.</p>
<h2>What still isn’t known</h2>
<p>Currently, our technology is best first used for urgent heart conditions, including restarting the heart after surgery, heart attack and ventricular defibrillation. We continue to explore its long-term effects and durability in the human body.</p>
<p>The body’s internal environment is <a href="https://doi.org/10.1017/jfm.2022.272">rich in fluids</a> that are disturbed by the heart’s constant mechanical motion. This could potentially compromise the device’s functionality over time. </p>
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<a href="https://images.theconversation.com/files/580750/original/file-20240308-28-ptbgx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="ECG reading of patient with pacemaker syndrome" src="https://images.theconversation.com/files/580750/original/file-20240308-28-ptbgx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580750/original/file-20240308-28-ptbgx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=303&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580750/original/file-20240308-28-ptbgx3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=303&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580750/original/file-20240308-28-ptbgx3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=303&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580750/original/file-20240308-28-ptbgx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=380&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580750/original/file-20240308-28-ptbgx3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=380&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580750/original/file-20240308-28-ptbgx3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=380&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Pacemaker syndrome is a condition that develops from stimulating heart muscles in isolation.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:E00031141_(CardioNetworks_ECGpedia).jpg">Michael Rosengarten BEng, MD.McGill/EKG World Encyclopedia via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>Moreover, researchers don’t fully understand how the body reacts to prolonged exposure to medical devices. The formation of <a href="https://theconversation.com/implants-like-pacemakers-and-insulin-pumps-often-fail-because-of-immune-attacks-stopping-them-could-make-medical-devices-safer-and-longer-lasting-211090">scar tissue</a> around the device after implantation can diminish its sensitivity. We are developing special surface treatments and biomaterial coatings to decrease the likelihood of rejection. </p>
<p>Although the breakdown of our device results in a nontoxic substance the body can safely absorb called <a href="https://doi.org/10.1038/s41578-020-0230-0">silicic acid</a>, evaluating how the body responds to extended implantation is essential to ensure safety and effectiveness.</p>
<h2>What’s next</h2>
<p>To achieve long-term implantation and tailor the device to each patient, we are refining the rate at which it dissolves naturally in the body. We are exploring enhancements to make the device compatible as a wearable pacemaker. This involves integrating a wireless light-emitting diode, or LED, beneath the skin that is connected to the device via an optical fiber.</p>
<p>Our ultimate goal is to broaden the scope of what we call photoelectroceuticals beyond cardiac care. This includes <a href="https://theconversation.com/brain-stimulation-can-rewire-and-heal-damaged-neural-connections-but-it-isnt-clear-how-research-suggests-personalization-may-be-key-to-more-effective-therapies-182491">neurostimulation</a>, neuroprostheses and pain management to treat neurodegenerative conditions such as <a href="https://www.parkinson.org/understanding-parkinsons/statistics">Parkinson’s disease</a>. </p>
<p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take on interesting academic work.</em></p><img src="https://counter.theconversation.com/content/224350/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pengju Li consults to the Pritzker School of Molecular Engineering. He receives funding from the University of Chicago.</span></em></p>Researchers designed an ultrathin pacemaker that can be implanted via minimally invasive techniques, potentially improving recovery time and reducing the risk of complications.Pengju Li, Ph.D. Candidate in Molecular Engineering, University of Chicago Pritzker School of Molecular EngineeringLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2174292023-12-11T13:12:20Z2023-12-11T13:12:20ZHow do pacemakers and defibrillators work? A cardiologist explains how they interact with the electrical system of the heart<figure><img src="https://images.theconversation.com/files/564019/original/file-20231206-17-jlxwsq.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2113%2C1419&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Electrocardiograms, or ECGs, record the electrical activity of your heart. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/heart-rate-monitor-royalty-free-image/523791776">Randy Faris/The Image Bank via Getty Images</a></span></figcaption></figure><p>Your heart’s job is to keep your pulse steady to pump blood throughout your body. Sometimes your heart rate is slower when you’re relaxing, and sometimes it’s faster when you’re exercising or stressed. If your heart’s ability to keep the beat starts to go awry, <a href="https://scholar.google.com/citations?view_op=list_works&hl=en&user=IM1QEMIAAAAJ">cardiac electrophysiologists like me</a> look for outside help from an implantable device.</p>
<p>There are two common implantable devices for the heart: <a href="https://www.nhlbi.nih.gov/health/pacemakers">artificial pacemakers</a> and <a href="https://www.nhlbi.nih.gov/health/defibrillators">defibrillators</a>. Artificial pacemakers keep blood and oxygen flowing during times of stress. Defibrillators are devices that detect dangerously fast heart rates and deliver shocks like those used during cardiopulmonary resuscitation, also known as CPR, to restart the heart.</p>
<p>Understanding how these devices work requires appreciating how the heart’s electrical system works and the weak links that cause malfunctions.</p>
<h2>The heart’s natural pacemaker system</h2>
<p>Abnormally slow heart rates result from breakdowns in two principal areas of the heart. </p>
<p>First, the <a href="https://www.ncbi.nlm.nih.gov/books/NBK459238/">sinoatrial, or SA, node</a> sets your “resting” heart rate, usually somewhere between 60 and 100 beats per minute. This is the base effort needed to circulate enough blood to sustain normal bodily function. Elevated levels of certain hormones circulating in the body, such as adrenaline and serotonin, can <a href="https://doi.org/10.3389/fphys.2020.00170">increase heart rate above resting levels</a>. </p>
<p>Trained athletes frequently have a lower resting heart rate due to extra physical conditioning. Like any other muscle, the heart becomes stronger with training. Because their heart functions more efficiently, athletes <a href="http://dx.doi.org/10.1136/heart.89.12.1455">require fewer heart beats overall</a> to circulate blood. </p>
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<a href="https://images.theconversation.com/files/564020/original/file-20231206-25-3nscgh.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram of cross-section of heart showing the SA and AV nodes" src="https://images.theconversation.com/files/564020/original/file-20231206-25-3nscgh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564020/original/file-20231206-25-3nscgh.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=541&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564020/original/file-20231206-25-3nscgh.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=541&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564020/original/file-20231206-25-3nscgh.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=541&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564020/original/file-20231206-25-3nscgh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=680&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564020/original/file-20231206-25-3nscgh.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=680&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564020/original/file-20231206-25-3nscgh.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=680&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Breakdowns in the sinoatrial and atrioventricular nodes can cause heart rate problems.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Conduction_system_en_(CardioNetworks_ECGpedia).png">Rob Kreuger, medical illustrator/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>The <a href="https://www.ncbi.nlm.nih.gov/books/NBK557664/">atrioventricular, or AV, node</a> is the second key area of the heart’s electrical wiring. The atrioventricular node takes information about how fast the heart is beating from the sinoatrial node and relays it to the ventricles, the muscular portions of the heart that allow it to pump blood to the rest of the body. </p>
<p>When the atrioventricular node breaks down, the ventricles don’t receive the electrical signal from the sinoatrial node instructing them to “pump,” or create a heartbeat. This causes heart rate to become dangerously slow. </p>
<h2>When heart rate is too slow</h2>
<p>If resting heart rate is abnormally low or fails to increase with hormonal changes, pacemakers can help keep blood and oxygen circulating at a healthy rate. </p>
<p>Both the SA node and the AV node <a href="https://doi.org/10.1146%2Fannurev-physiol-021119-034453">naturally slow with age</a>, but sometimes this happens at an accelerated pace and leads to abnormally slow heart rates. Slow heart rates can also be caused by other diseases, including <a href="https://www.thyroid.org/patient-thyroid-information/ct-for-patients/february-2020/vol-13-issue-2-p-3-4/">thyroid problems</a> and <a href="https://theconversation.com/lyme-carditis-things-can-get-complicated-when-lyme-disease-affects-heart-function-167045">Lyme disease</a>. In these cases, slow rates are treatable without a pacemaker.</p>
<p>A common <a href="https://www.nhlbi.nih.gov/health/pacemakers/how-it-works">pacemaker system</a> has a battery and two wires that can send and receive electrical signals. One wire rests near the sinoatrial node, and the second in one of the heart’s ventricles. </p>
<p>If the wire near the sinoatrial node doesn’t detect any electrical activity over a set time, the pacemaker’s battery will send an impulse to the ventricle to initiate an electrical signal. Within fractions of a second, the wire in the ventricle should detect that electrical activity. If an impulse is detected, this signifies that the AV node conducted the signal correctly to the rest of the heart, and the pacemaker does not activate. If the wire doesn’t receive this signal, the battery delivers an impulse through the wire directly to the ventricle, causing the muscle to contract and initiate a heartbeat.</p>
<p>The heart’s muscle will only contract in response to a pacemaker impulse if the muscle is otherwise healthy. Pacemakers <a href="https://scienceillustrated.com.au/blog/medicine/ask-us-will-pacemakers-still-work-after-death/">do not keep patients alive</a> if the heart shuts down, such as during a massive infection, blood clot or kidney failure. Pacemakers simply keep the heart rate in a comfortable range if the primary problem in the heart is electrical.</p>
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<a href="https://images.theconversation.com/files/564018/original/file-20231206-34417-smw7n5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram of cross-section of heart with implanted pacemaker" src="https://images.theconversation.com/files/564018/original/file-20231206-34417-smw7n5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564018/original/file-20231206-34417-smw7n5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=505&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564018/original/file-20231206-34417-smw7n5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=505&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564018/original/file-20231206-34417-smw7n5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=505&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564018/original/file-20231206-34417-smw7n5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=635&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564018/original/file-20231206-34417-smw7n5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=635&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564018/original/file-20231206-34417-smw7n5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=635&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Pacemaker electrodes are implanted directly in the heart.</span>
<span class="attribution"><a class="source" href="https://www.nhlbi.nih.gov/sites/default/files/inline-images/images_279.jpg">National Heart, Lung, and Blood Institute</a></span>
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<p>Doctors program a pacemaker’s software so the resting pulse doesn’t drop below a certain rate, commonly 50 to 60 beats per minute. If the resting rate is set at 60 beats per minute, the pacemaker will wait exactly one second before initiating an electrical pulse. The heart’s pulse rate can be higher than this number if the sinoatrial node initiates a heartbeat naturally. If the pacemaker detects activity from the sinoatrial node, it will reset its timer for another full second. </p>
<p>Modern pacemakers also contain sensors to predict whether the heart may benefit from a faster heart rate under certain circumstances. For example, pacemaker batteries <a href="https://doi.org/10.1111/jce.14733">contain accelerometers</a> like those used in pedometers to detect if a person is in motion. If these sensors activate, the pacemaker can raise its minimum rate like how the heart would normally respond to exercise. Sensors can also detect if a person begins to breathe more quickly or if the heart begins to contract more powerfully, all signs normally associated with increases in heart rate. </p>
<h2>When heart rate is too fast</h2>
<p>Like pacemakers, a <a href="https://www.nhlbi.nih.gov/health/defibrillators/how-do-defibrillators-work">cardiac defibrillator</a> comes with a battery and wires that record the heart’s rate. But instead of treating slow heart rates, defibrillators are programmed to detect fast heart rates, usually in the range of 200 beats per minute. Heart rates in this range are often caused by <a href="https://www.ncbi.nlm.nih.gov/books/NBK532954/">ventricular tachycardia</a> or <a href="https://www.ncbi.nlm.nih.gov/books/NBK537120/">ventricular fibrillation</a>, which are potentially lethal heart rhythms resulting from the lower chamber of the heart beating too quickly or quivering.</p>
<p>Certain people are at elevated risk for these types of rhythm disturbances. Many <a href="https://doi.org/10.1093/eurheartj/ehad015">cases of “sudden death”</a> in athletes and other young people are either suspected or proved to be related to ventricular fibrillation. </p>
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<figcaption><span class="caption">Defibrillators deliver an electric charge to restart the heart.</span></figcaption>
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<p>Defibrillators deliver internal shocks to the heart when their sensors detect either ventricular tachycardia or ventricular fibrillation. These shocks stop the heart for a fraction of a second to give the sinoatrial node a chance to resume its normal activity. These shocks <a href="https://abcnews.go.com/Health/HeartRhythmTreatment/story?id=5213935#">can be painful</a>, so doctors usually also prescribe medications or other procedures to help prevent needing the shocks in the first place. </p>
<p>A defibrillator is like a seatbelt: It is reassuring to have, but ideally it never needs to be deployed. </p>
<h2>Beyond the surgery</h2>
<p>Pacemakers and defibrillators do require some maintenance. Certain settings, such as how low the pacemaker will allow the pulse to go, <a href="https://doi.org/10.1111/j.1540-8159.2007.00968.x">can be adjusted over time</a>. Doctors have computers that can communicate with the devices and alter their programming. Some devices use Bluetooth technology. </p>
<p>The battery cannot be recharged and must be replaced, generally after six to 10 years. <a href="https://doi.org/10.1093/europace/eun359">Battery life</a> depends on how frequently the heart requires the pacemaker to initiate heartbeats. <a href="https://doi.org/10.5603/KP.2015.0147">Pacemaker wires</a> occasionally need to be replaced if they fracture or if the insulation wears down after years of bending with each heartbeat. On rare occasions, pacemaker parts are recalled. Usually these parts do not require replacement but <a href="https://doi.org/10.1007%2Fs12471-015-0669-6">may require special attention</a>. More frequent checkups of the electrical “health” of the devices are usually prescribed for early detection of any problems with battery life or wire failures.</p>
<p>Pacemakers and defibrillators are always changing, in part to keep up with medical and nonmedical technologies.</p>
<p>With cloud-based management systems that make medical information available to doctors in real time, <a href="https://theconversation.com/three-reasons-why-pacemakers-are-vulnerable-to-hacking-83362">security has become a major focus</a> of modern pacemaker software. Other medical technologies such as MRIs can change how pacemakers and defibrillators work if not handled carefully – MRIs create electromagnetic impulses that cardiac devices <a href="https://doi.org/10.1148/radiol.2018180285">can misinterpret as heartbeats</a>. Modern devices are engineered with these factors in mind, but still require careful programming for these special circumstances.</p>
<p>When used correctly, pacemakers and defibrillators improve both quality of life and life expectancy. While teams of engineers design these small machines, they rely on doctors knowing who will benefit from this technology and how to program the software to best serve each specific patient and scenario.</p><img src="https://counter.theconversation.com/content/217429/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Virginia Singla consults for Medtronic. </span></em></p>Heart rates that are too slow or too fast can sometimes be lethal. Medical implants can help the heart get its rhythm back.Virginia Singla, Clinical Assistant Professor of Cardiology, University of PittsburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2110902023-09-25T15:03:20Z2023-09-25T15:03:20ZImplants like pacemakers and insulin pumps often fail because of immune attacks − stopping them could make medical devices safer and longer-lasting<figure><img src="https://images.theconversation.com/files/549651/original/file-20230921-21-b8f110.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2121%2C1412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Foreign body responses can cause insulin pumps to degrade.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-diabetic-patient-keeps-an-insulin-pump-in-the-royalty-free-image/1041117870">Click_and_Photo/iStock via Getty Images</a></span></figcaption></figure><p>Biomedical implants – such as pacemakers, breast implants and orthopedic hardware like screws and plates to replace broken bones – have improved patient outcomes across a wide range of diseases. However, <a href="https://doi.org/10.1002%2Fbtm2.10300">many implants fail</a> because the body rejects them, and they need to be removed because they no longer function and can cause pain or discomfort.</p>
<p>An immune reaction called the <a href="https://doi.org/10.1002/adfm.202007226">foreign body response</a> – where the body encapsulates the implant in sometimes painful scar tissue – is a key driver of implant rejection. Developing treatments that target the mechanisms driving foreign body responses could improve the design and safety of biomedical implants.</p>
<p>I am a <a href="https://scholar.google.com/citations?user=TG52tUAAAAAJ&hl=en">biomedical engineer</a> who studies why the body forms scar tissue around medical devices. Along with my colleagues <a href="https://scholar.google.com/citations?user=XMWljcMAAAAJ&hl=en">Dharshan Sivaraj</a>, <a href="https://scholar.google.com/citations?user=UcM7zG8AAAAJ&hl=en">Jagan Padmanabhan</a> and <a href="https://scholar.google.com/citations?user=zY_J9IQAAAAJ&hl=en">Geoffrey Gurtner</a>, we wanted to learn more about what causes foreign body responses. In our research, recently published in the journal Nature Biomedical Engineering, we <a href="https://www.nature.com/articles/s41551-023-01091-5">identified a gene</a> that appears to drive this reaction because of the increased stress implants put on the tissues surrounding them.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/4h9nfYbov38?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Many implants need to be replaced because the immune system damages them over time.</span></figcaption>
</figure>
<h2>Mechanics of implant rejection</h2>
<p>Researchers hypothesize that foreign body responses are triggered by the chemical and material composition of the implant. Just as a person can tell the difference between touching something soft like a pillow versus something hard like a table, cells can tell when there are changes to the softness or stiffness of the tissues surrounding them as a result of an implant.</p>
<p>The <a href="https://doi.org/10.1096/fj.202101354">increased mechanical stress</a> on those cells sends a signal to the immune system that there is a foreign body present. Immune cells activated by mechanical pressure respond by building a capsule made of scar tissue around the implant in an attempt to shield it off. The more severe the immune reaction, the thicker the capsule. This protects the body from getting an infection from injuries like a splinter in your finger.</p>
<p>All biomedical implants cause some level of foreign body response and are surrounded by at least a small capsule. Some people have very strong reactions that result in a large, thick capsule that constricts around the implant, impeding its function and causing pain. <a href="https://doi.org/10.1002%2Fbtm2.10300">Between 10% to 30% of implants</a> need to be removed because of this scar tissue. For example, a neurostimulator could trigger the formation of a dense capsule of scar tissue that <a href="https://doi.org/10.1073/pnas.2115857119">inhibits electrical stimulation</a> from properly reaching the nervous system.</p>
<p>To understand why the immune systems of some people build thick capsules around implants while others do not, we gathered capsule samples from 20 patients whose breast implants were removed – 10 who had severe reactions, and 10 who had mild reactions. By genetically analyzing the samples, we found that a <a href="https://www.nature.com/articles/s41551-023-01091-5">gene called RAC2</a> was highly expressed in samples taken from patients with severe reactions but not in those with mild reactions. This gene is found <a href="https://doi.org/10.1128/mcb.22.21.7645-7657.2002">only in immune cells</a>, and it codes for a <a href="https://doi.org/10.1074/jbc.M306491200">member of a family of proteins</a> involved in cell growth and structure.</p>
<p>Because this protein seemed to be linked to a lot of the downstream reactions that lead to foreign body responses, we decided to explore how RAC2 affects the formation of capsules. We found that immune cells activate RAC2 along with other proteins <a href="https://www.nature.com/articles/s41551-023-01091-5">in response to mechanical stress</a> from implants. These proteins summon additional immune cells to the area that <a href="https://doi.org/10.3390%2Fma8095269">combine into a massive clump</a> to attack a large invader. These combined cells spit out fibrous proteins like collagen that form scar tissue.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/549655/original/file-20230921-25-uccyoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Clinician holding a silicone breast implant" src="https://images.theconversation.com/files/549655/original/file-20230921-25-uccyoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/549655/original/file-20230921-25-uccyoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/549655/original/file-20230921-25-uccyoe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/549655/original/file-20230921-25-uccyoe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/549655/original/file-20230921-25-uccyoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/549655/original/file-20230921-25-uccyoe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/549655/original/file-20230921-25-uccyoe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The mechanical stress that medical devices like breast implants place on surrounding tissues can trigger a foreign body response.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/plastic-surgeon-holding-breast-silicone-implant-royalty-free-image/1300316377">megaflopp/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>To confirm RAC2’s role in foreign body responses, we artificially stimulated the mechanical signaling proteins surrounding silicone implants surgically placed in mice. This stimulation produced a severe and humanlike foreign body response in the mice. In contrast, blocking RAC2 resulted in an <a href="https://www.nature.com/articles/s41551-023-01091-5">up to threefold reduction</a> in foreign body responses.</p>
<p>These findings suggest that activating mechanical stress pathways triggers immune cells with RAC2 to generate severe foreign body responses. Blocking RAC2 in immune cells may significantly reduce this reaction.</p>
<h2>Developing new treatments</h2>
<p>Implant failure is conventionally treated by using <a href="https://doi.org/10.1186/s13036-019-0209-9">biocompatible materials</a> that the body can better tolerate, such as certain polymers. These don’t completely remove the risk of foreign body reactions, however.</p>
<p>My colleagues and I believe that treatments that target the pathways associated with RAC2 could potentially mitigate or prevent free body responses. Heading off this reaction would help improve the effectiveness and safety of medical implants.</p>
<p>Because <a href="https://doi.org/10.1128/mcb.22.21.7645-7657.2002">only immune cells express RAC2</a>, a drug designed to block only that gene would theoretically target only immune cells without affecting other cells in the body. Such a drug could also be administered via injection or even coated onto an implant to minimize side effects.</p>
<p>A complete understanding of the molecular mechanisms driving foreign body responses would be the final frontier in developing truly bio-integrative medical devices that could integrate with the body with no problems for the recipient’s entire life span.</p><img src="https://counter.theconversation.com/content/211090/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kellen Chen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>From breast implants to prosthetic knees, implants can trigger a foreign body response that results in your body rejecting them. Suppressing an immune cell gene could reduce this risk.Kellen Chen, Assistant Professor of Surgery, University of ArizonaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1564222021-03-05T12:15:32Z2021-03-05T12:15:32Z‘Backup’ pacemaker discovery in goats could have important implications for human hearts<figure><img src="https://images.theconversation.com/files/387996/original/file-20210305-15-1fny9wc.jpg?ixlib=rb-1.1.0&rect=11%2C0%2C3882%2C2550&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This research could change our understanding of the heart.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/anatomy-human-heart-233628424">Liya Graphics/ Shutterstock</a></span></figcaption></figure><p>Your heart beats around 60 times a minute, delivering nutrients and removing waste from every cell in your body. It has been doing this since you were in the womb – the heart forms <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1767747/">18 days into foetal development</a> and begins to <a href="https://www.karger.com/Article/Fulltext/501906">pump</a> blood about three days later. </p>
<p>But for all we know about this vital organ, researchers are still learning new things about it. </p>
<p>In fact, a recent study in goats found the heart has a built-in “reserve pacemaker” which has the potential to take over when the mechanism that normally ensures the heart keeps beating, known as the SA node, fails. </p>
<p>This could have important implications for humans, whose <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4834612/">heart is very similar</a> in structure, particularly in studying conditions that affect the SA node, such as arrhythmia.</p>
<h2>The pacemaker</h2>
<p>The heart is made of a cardiac muscle. Unlike other muscles in the body (like those controlling our eyes and legs), we can’t control it. Instead, the <a href="https://royalsocietypublishing.org/doi/10.1098/rsta.2015.0181">heart’s speed</a> is controlled by the <a href="https://www.ncbi.nlm.nih.gov/books/NBK539845/">autonomic nervous system</a>. </p>
<p>The nerves that relay input about our required heart rate connect to a specialised centre in the wall of the right atrium (one of the heart’s four chambers), known as the sinoatrial (SA) node. </p>
<p>The SA node is composed of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4711507/">specialised pacemaker cells</a>, which send out an electrical impulse throughout the cardiomyocytes (cardiac cells), ensuring the <a href="https://theconversation.com/curious-kids-how-does-our-heart-beat-102609">heart beats properly</a>.</p>
<p>But the SA node can be dysfunctional. These faults can be <a href="https://www.ncbi.nlm.nih.gov/books/NBK544253/">acquired</a> or <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2913508/">inherited</a>. Acquired dysfunction is more common, often caused by <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4139053/">age</a>, certain medications and lifestyle factors such as an increased <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4139053/">BMI</a>, <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215687#pone.0215687.">diabetes</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/8114238/">hypertension</a>. Many people who have a dysfunction may not have symptoms. </p>
<figure class="align-center ">
<img alt="An illustration of an artificial pacemaker inside the body." src="https://images.theconversation.com/files/387999/original/file-20210305-13-boghvg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/387999/original/file-20210305-13-boghvg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=483&fit=crop&dpr=1 600w, https://images.theconversation.com/files/387999/original/file-20210305-13-boghvg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=483&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/387999/original/file-20210305-13-boghvg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=483&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/387999/original/file-20210305-13-boghvg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=606&fit=crop&dpr=1 754w, https://images.theconversation.com/files/387999/original/file-20210305-13-boghvg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=606&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/387999/original/file-20210305-13-boghvg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=606&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artificial pacemakers act like the SA node.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/medical-illustration-permanent-pacemaker-implant-3d-1487085152">peterschreiber.media/ Shutterstock</a></span>
</figcaption>
</figure>
<p>One of the most common symptoms of a dysfunctional SA node, experienced by about two million people a year in the UK, is an <a href="https://www.nhs.uk/conditions/arrhythmia/">arrhythmia</a>. This is where the heart beats too fast, too slow or irregularly. </p>
<p>There are a variety of treatment options for arrhythmia including <a href="https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/drug-cabinet/anti-arrhythmics">medication</a>, <a href="https://www.bhf.org.uk/informationsupport/treatments/cardioversion">cardioversion</a> (electric signals used to get heart rate back to normal), <a href="https://www.nhlbi.nih.gov/health-topics/pacemakers">pacemakers</a> (a medical device that delivers electrical impulses) and <a href="https://www.mayoclinic.org/tests-procedures/cardiac-ablation/about/pac-20384993">cardiac ablation</a> (using energy delivered through tubes inserted into your vessels to destroy the heart’s damaged or malfunctioning tissue). </p>
<p>These techniques have mixed levels of success and any surgical intervention carries risk.</p>
<h2>Keeping the beat</h2>
<p><a href="https://www.frontiersin.org/articles/10.3389/fphys.2021.592229/full">New research</a> might change our understanding of how the heart works. A study from researchers in the UK, Pakistan and Poland found that other areas of the heart located around the SA node can also act as a pacemaker – particularly in instances where the SA node has stopped functioning, such as in the case of an arrhythmia. </p>
<p>The researchers found that the nearby subsidiary atrial pacemaker takes over when the SA node fails, and keeps the heart beating as normal.</p>
<p>Although the study was conducted on goats, these results are still promising for humans, as our hearts share <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654199/">many similarities</a> in structure and function. </p>
<figure class="align-center ">
<img alt="Two goats in a field." src="https://images.theconversation.com/files/388019/original/file-20210305-15-gyclu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/388019/original/file-20210305-15-gyclu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/388019/original/file-20210305-15-gyclu8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/388019/original/file-20210305-15-gyclu8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/388019/original/file-20210305-15-gyclu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/388019/original/file-20210305-15-gyclu8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/388019/original/file-20210305-15-gyclu8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Our hearts aren’t too different from a goat’s.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/two-goats-look-camera-794370853">Linas T/ Shutterstock</a></span>
</figcaption>
</figure>
<p>The findings are particularly exciting as they may present new opportunities for treating SA node dysfunction through potentially less invasive means, where natural populations of cells near the SA node, such as in the subsidiary atrial pacemaker, show the ability to take over as the dominant pacemaker of the heart, and keep it beating as normal.</p>
<p>The development of the SA node and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1768983/">how it grows</a> is still not fully understood, so it comes as no surprise to some that there are other similar cells in the heart with similar capabilities. </p>
<p>The subsidiary atrial pacemaker that has been discovered will require further investigation to see whether these cells come from SA node cells as they develop, or if they migrate to their location or form from elsewhere in the heart.</p>
<p>When the study’s researchers performed an electrocardiogram (ECG), which checks the heart’s rhythm and electrical activity, they found remarkable similarities between the activity of both the SA node and subsidiary atrial pacemaker. The electrical activity of the heart and its output was maintained even when the SA node had failed, showing that the cells of this “backup” pacemaker are more than up to the job. The presence of <a href="https://www.uniprot.org/uniprot/Q9Y3Q4">certain</a> <a href="https://www.uniprot.org/uniprot/P32418">key proteins</a> shows these subsidiary cells can generate enough power to keep the heart functioning as normal.</p>
<p>Involvement of other areas of the atrial wall in generating pacemaker signals have been <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3543718/">documented</a> in a condition known as <a href="https://pubmed.ncbi.nlm.nih.gov/25594484/">wandering</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4910492/">atrial</a> pacemaker, showing the potential for electrical impulses to come from other <a href="https://www.heartrhythmjournal.com/article/S1547-5271(09)01177-1/fulltext">areas</a> of the wall.</p>
<p>The discovery of this “backup” pacemaker may provide the answer as to why performing a cardiac ablation on people with a dysfunctional SA node isn’t always successful. </p>
<p>As we begin to understand more about this new structure, it may be that there is a reduced need for artificial pacemakers to be fitted for SA node conditions.</p><img src="https://counter.theconversation.com/content/156422/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor is affiliated with the Anatomical Society. </span></em></p>This ‘backup’ pacemaker can keep the heart beating as normal when the mechanism which normally keeps the heart beating fails.Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1548232021-02-08T06:11:47Z2021-02-08T06:11:47ZGot an implantable defibrillator or a pacemaker? Keep your iPhone 12 in your trouser pocket, not your shirt<figure><img src="https://images.theconversation.com/files/382931/original/file-20210208-13-xlbql8.jpg?ixlib=rb-1.1.0&rect=53%2C0%2C6000%2C3988&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shuttertock</span></span></figcaption></figure><p>There are <a href="https://www.heartrhythmjournal.com/article/S1547-5271(20)31227-3/fulltext">increasing concerns</a> the new Apple iPhone 12 could interfere with implantable cardiac devices such as pacemakers, presenting a risk for people with heart problems.</p>
<p>The issue relates to a particular feature of the iPhone 12 — a new magnetic charging technology called <a href="https://www.macworld.co.uk/feature/complete-guide-magsafe-3607036/">MagSafe</a> — which uses magnets to attach wireless charging accessories to the phone. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1357738018363355137"}"></div></p>
<p>Patients with implantable cardiac devices are being warned keeping their iPhone 12 too close to their chest, such as in a shirt pocket or handbag, could cause temporary disruptions to their cardiac device’s functions.</p>
<p>So how does this happen, and what do you need to know if you’ve got both an implanted cardiac device and an iPhone 12?</p>
<h2>First, some background</h2>
<p>Pacemakers, and another type of implantable cardiac device called implantable cardioverter defibrillators, are both used widely in health care.</p>
<p><a href="https://www.svhhearthealth.com.au/procedures/procedures-treatments/pacemaker">Pacemakers</a> have traditionally been used to regulate a person’s heartbeat, particularly if it’s slow.</p>
<p><a href="https://www.svhhearthealth.com.au/procedures/procedures-treatments/implantable-defibrillator">Implantable cardioverter defibrillators</a> regulate the heart’s rhythm in people who experience heart rhythm disorders, such as ventricular arrhythmias. These devices can also deliver <a href="https://heart.bmj.com/content/104/3/230.abstract">defibrillation</a> (a shock) to restore a normal heart rhythm in the event of a sudden, life-threatening arrhythmia.</p>
<p>Implantable cardioverter defibrillators have been shown to improve survival for people with heart rhythm problems, and they’re becoming <a href="https://www.mja.com.au/journal/2018/209/3/implantable-cardioverter-defibrillator-therapy-australia-2002-2015">more common</a> in Australia.</p>
<p>Around <a href="https://www1.racgp.org.au/ajgp/2018/may/cardiac-rhythm-management-devices#:%7E:text=There%20are%20approximately%20200%2C000%20pacemakers,cause%20for%20an%20MRI%20scan.">200,000 Australians</a> have a pacemaker or defibrillator implanted. It’s also now common to have a dual-function implantable cardioverter defibrillator and pacemaker.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/apples-iphone-12-comes-without-a-charger-a-smart-waste-reduction-move-or-clever-cash-grab-148189">Apple's iPhone 12 comes without a charger: a smart waste-reduction move, or clever cash grab?</a>
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<h2>So what’s going on?</h2>
<p>MagSafe was developed with a view to removing the need for charging cables between the phone and the charger. Instead, a ring of <a href="https://www.macworld.co.uk/feature/complete-guide-magsafe-3607036/">magnets built around a charging coil</a> inside the back of the iPhone connects the phone magnetically with various charging accessories.</p>
<p>Implantable cardiac devices work by sending electrical impulses to the heart. Magnetic and electrical fields are related — electrically charged particles that <a href="https://www.livescience.com/32633-how-do-magnets-work.html">align in the same direction</a> generate a magnetic field. </p>
<p>Most magnets are made from materials called alloys. Variations in the combination of alloys creates <a href="https://science.howstuffworks.com/magnet.htm">different types of magnets</a> with different strengths. Ceramic magnets, such as those we use on the fridge, are not particularly strong, so won’t interfere with cardiac devices.</p>
<p>But the magnets inside the iPhone 12 and MagSafe accessories contain <a href="https://www.apple.com/environment/pdf/products/iphone/iPhone_12_PER_Oct2020.pdf">100% recycled rare-earth elements</a>. <a href="https://www.magnetsource.com/pages/rare-earth-magnets">Rare-earth magnets</a> are the strongest type of hard magnets on the market today — and strong enough to cause an interaction between the phone and the cardiac device.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/in-cases-of-cardiac-arrest-time-is-everything-community-responders-can-save-lives-126491">In cases of cardiac arrest, time is everything. Community responders can save lives</a>
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<h2>Implantable defibrillators are designed to react with magnets</h2>
<p>When clinicians need to deactivate implantable cardiac devices, they generally use magnets. Implantable cardioverter defibrillators, for example, <a href="https://www.aci.health.nsw.gov.au/__data/assets/pdf_file/0008/179990/ACI-Deactivate-ICDs.pdf">may be deactivated for a range of reasons</a>, including because it’s the patient’s preference, or when they’re nearing the end of their life.</p>
<p>Pacemakers and implantable cardioverter defibrillators have an inbuilt switch that reacts to externally applied magnetic fields. So clinicians can apply a clinical ring magnet to temporarily deactivate the device. We call this “magnet mode”.</p>
<figure class="align-center ">
<img alt="An x-ray showing an implantable cardioverter defibrillator." src="https://images.theconversation.com/files/382960/original/file-20210208-13-11eoqzb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/382960/original/file-20210208-13-11eoqzb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/382960/original/file-20210208-13-11eoqzb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/382960/original/file-20210208-13-11eoqzb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/382960/original/file-20210208-13-11eoqzb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/382960/original/file-20210208-13-11eoqzb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/382960/original/file-20210208-13-11eoqzb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Implantable cardioverter defibrillators can save someone from a life-threatening arrhythmia. But the iPhone 12 could interfere with the device’s functions.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>It appears proximity to an iPhone 12 also causes “magnet mode” to kick in. Recently, <a href="https://www.heartrhythmjournal.com/article/S1547-5271(20)31227-3/fulltext">a team of cardiologists</a> tested the interaction between the iPhone 12 and an implantable cardioverter defibrillator. They noted immediate suspension of the implantable cardioverter defibrillator, which persisted as long as the iPhone was placed over the left side of the chest, in a shirt pocket. </p>
<p>When an implantable cardioverter defibrillator is in “magnet mode”, it’s reprogrammed to manufacturer settings, and the arrhythmia detection and treatment functions are deactivated or disabled. Temporary pacing modes are not affected, so the implantable cardioverter defibrillator can still increase heart rate if it’s slow. </p>
<p><a href="https://www.medtronic.com/au-en/patients/electromagnetic-guide/frequently-asked-questions.html">Removing the magnet</a> (the iPhone) should return the implantable cardioverter defibrillator to its previous program settings. But even a temporary disruption to this technology could potentially be dangerous.</p>
<p>We haven’t been able to find information describing any real-world cases of interference caused by the iPhone 12, and scientists are yet to test the effect of an iPhone 12 on a pacemaker.</p>
<p>But the evidence we have so far has prompted experts to draw attention to the issue.</p>
<h2>Advice for people with implantable defibrillators and pacemakers</h2>
<p>The Heart Foundation and the Australian and New Zealand Cardiac Device Advisory and Complication Committee have both <a href="https://www.theaustralian.com.au/business/technology/fresh-warnings-on-apple-iphone-12-magnets-and-implants/news-story/9f091f66d124c74071c6b821af5c0d4b#:%7E:text=Two%20Australian%20cardiac%20focused%20bodies,to%20external%20chargers%20and%20accessories.">warned</a> iPhone 12 users with these implants to avoid placing the iPhone 12 in a top shirt pocket. </p>
<p>Apple has <a href="https://support.apple.com/en-us/HT211900">acknowledged the issue</a>, recommending iPhone 12 users keep their iPhone and MagSafe accessories a safe distance away from their implantable cardiac devices. They specify 15cm apart, or more than 30cm apart if the phone is wirelessly charging. </p>
<p>Apple has also recommended patients consult their doctor and device manufacturer for device-specific recommendations.</p>
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Read more:
<a href="https://theconversation.com/digital-diagnosis-how-your-smartphone-or-wearable-device-could-forecast-illness-102385">Digital diagnosis: How your smartphone or wearable device could forecast illness</a>
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<p>If you have an implantable cardioverter defibrillator or a pacemaker, avoid storing your iPhone 12 in the left-hand shirt pocket or in a handbag on your left arm. A pocket in your pants will be safer.</p>
<p>And it’s a good idea to speak with your health-care professional about magnetic sensitivity and your device during your next visit.</p><img src="https://counter.theconversation.com/content/154823/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Caleb Ferguson receives funding from the National Health & Medical Research Council and the Heart Foundation.</span></em></p><p class="fine-print"><em><span>Rochelle Wynne does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The new magnetic charging technology which is a feature of Apple’s iPhone 12 could wreak havoc with implantable cardiac devices. Here’s what we know.Caleb Ferguson, Senior Research Fellow, Western Sydney Nursing & Midwifery Research Centre, Western Sydney Local Health District &, Western Sydney UniversityRochelle Wynne, Director, Western Sydney Nursing & Midwifery Research Centre, Western Sydney UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/833572017-09-07T03:54:07Z2017-09-07T03:54:07ZAssassination by pacemaker: Australia needs to do more to regulate internet-connected medical devices<figure><img src="https://images.theconversation.com/files/184831/original/file-20170906-9830-1sg515t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Australia's medical regulator needs to do more about cybersecurity.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dddr-pacemaker-xray-image-cardiac-catheterization-441650620?src=blj2MLS4Anocx1W3Ze3OnQ-1-20">Korawig Boonsua/Shutterstock</a></span></figcaption></figure><p>In the future, people are going to be just a little bit cyborg. We’ve accepted hearing aids, nicotine patches and spectacles, <a href="https://www.embs.org/about-biomedical-engineering/our-areas-of-research/wearable-implantable-technologies/">but implanted</a> medical devices that are internet-connected present new safety challenges. Are Australian regulators keeping up?</p>
<p>A global recall <a href="https://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm573669.htm">of pacemakers</a> has sparked new fears and splashy headlines about hacked medical devices. But the next 20 years of medicine will normalise the use of intelligent implants to control pain, provide data for diagnostic purposes and supplement ailing organs, which means we need proper security as well as access in case of emergency. </p>
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Read more:
<a href="https://theconversation.com/three-reasons-why-pacemakers-are-vulnerable-to-hacking-83362">Three reasons why pacemakers are vulnerable to hacking</a>
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<p>Pharmaceuticals and medical devices in Australia are regulated by the <a href="https://www.tga.gov.au/tga-basics">Therapeutic Goods Administration</a> (TGA), an arm of the national Health Department. </p>
<p>Can we rely on Australia’s medical devices regime? Recurrent criticisms by parliamentary committees and government inquiries suggest the regulator may be struggling.</p>
<h2>The job of the TGA</h2>
<p>The TGA regulates medical devices such as stents, pacemakers, joint implants, <a href="https://theconversation.com/victims-of-faulty-breast-implants-were-let-down-by-the-tga-13074">breast implants</a>, and the controversial <a href="https://theconversation.com/vaginal-mesh-controversy-shows-collective-failure-of-the-tga-and-australias-specialists-78605">vaginal mesh</a> that has featured recently in the media (and a <a href="http://www.smh.com.au/national/pelvic-mesh-victims-blamed-by-asleep-at-wheel-health-system-inquiry-to-hear-20170719-gxehqv.html">Senate inquiry</a>) over claims it seriously injured patients.</p>
<p>The role of the TGA is vital, because defective devices can result in injury or death. They have a major cost for the public health system and affect patient quality of life. They often result in litigation, sometimes with <a href="http://www.reuters.com/article/us-johnson-johnson-verdict-hipimplants-idUSKBN13Q5XF">billion-dollar</a> <a href="http://www.abc.net.au/news/2016-03-31/class-action-over-defective-hip-replacements-settles-for-$250m/7288350">settlements</a>.</p>
<p>In undertaking its mission, the TGA looks to information from <a href="https://www.theguardian.com/australia-news/2017/jul/10/johnson-johnson-tried-to-prevent-report-about-pelvic-mesh-devices-court-hears">manufacturers</a> and distributors, from overseas regulators and its <a href="https://www.tga.gov.au/publication/therapeutic-product-vigilance">own staff</a>. </p>
<p>Like counterparts such as the US <a href="https://www.youtube.com/watch?v=UVUHEtrbL7A">Food and Drug Administration</a>, TGA staff are under pressure to get products into the marketplace and reduce “<a href="https://www.tga.gov.au/sites/default/files/tga-business-plan-2016-17.pdf">red tape</a>”.</p>
<h2>The TGA and cybersecurity</h2>
<p>Wireless medical devices need greater security than, say, an internet-connected fridge. It is axiomatic that they must work. </p>
<p>We need to ensure that information <a href="https://www.wired.com/2017/03/medical-devices-next-security-nightmare/">provided</a> by the devices is safeguarded and that control of the devices – <a href="https://spqr.eecs.umich.edu/papers/b1kohFINAL2.pdf">implantable</a> or otherwise – is not compromised. </p>
<p>To do that, we can use existing tools such as robust passwords, encryption and systems design. It also requires product vendors and practitioners to avoid negligence. Regulators must proactively foster and enforce standards. </p>
<p>Put simply, bodies like the TGA need to deal with software rather than simply bits of metal and plastic. It is unclear whether the TGA has the expertise or means to do so. </p>
<h2>Solutions, not panic</h2>
<p>The past decade has seen a succession of inquiries into the TGA, including the 2015 <a href="https://www.tga.gov.au/mmdr">Sansom Review</a> and 2012 Senate <a href="http://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Community_Affairs/Completed_inquiries/2010-13/implants2012/report/index">PIP Inquiry</a>. Each has demonstrated that the TGA is not always <a href="https://theconversation.com/consumers-lose-out-as-tga-reform-turns-into-a-hot-potato-13383">keeping up</a> with its task. </p>
<p>Problems are ongoing: think defective joint implants, <a href="https://theconversation.com/victims-of-faulty-breast-implants-were-let-down-by-the-tga-13074">breast implants</a> and <a href="http://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Community_Affairs/MeshImplants">vaginal mesh</a>. But there are some potential paths towards improvement.</p>
<p><strong>Accountability</strong></p>
<p>One solution is to ensure the TGA is more accountable. </p>
<p>Currently, if someone wishes to bring a claim alleging a device was improperly permitted, the TGA has <a href="https://www.legislation.gov.au/Series/C2004A03952">immunity</a> from civil litigation about regulatory failure. </p>
<p>Removal of immunity will force it to focus on outcomes. That can be reinforced by giving it independence from the Department of Health, making it report direct to Parliament and ensuring the openness emphasised by the <a href="http://pandora.nla.gov.au/pan/141595/20130902-0954/www.health.gov.au/internet/ministers/publishing.nsf/Content/mr-yr10-ck-ck005d526.htm?OpenDocument&yr=2010&mth=11">Pearce Inquiry</a>. </p>
<p><strong>Regulatory capture</strong></p>
<p>Medical products regulation in Australia has been a matter of penny wise, pound poor. The TGA is <a href="https://www.tga.gov.au/cost-recovery-implementation-statement-2016-17">funded</a> by fees from the manufacturers and distributors that it regulates, in addition to some government funding. </p>
<p>It needs a discrete budget that recoups costs but is not dependent on companies that complain regulation is expensive. It needs enough resources to do its job well in the emerging age of the internet of things, including access to independent expertise regarding cybersecurity and devices. </p>
<p><strong>A device register</strong></p>
<p>How many devices have been implanted and how many removed? The lack of data about medical devices is a problem.</p>
<p>The government has so far not embraced recommendations for a comprehensive device register, one allowing timely identification of what was implanted and by whom. </p>
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Read more:
<a href="https://theconversation.com/vaginal-mesh-controversy-shows-collective-failure-of-the-tga-and-australias-specialists-78605">Vaginal mesh controversy shows collective failure of the TGA and Australia's specialists</a>
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<p>Such a register would provide a means for determining problems with devices or medical practice. We need timely, consistent reporting of problems on a mandatory basis, as well as recall and <a href="http://pandora.nla.gov.au/pan/141595/20130902-0954/www.health.gov.au/internet/ministers/publishing.nsf/Content/mr-yr10-ck-ck005d526.htm?OpenDocument&yr=2010&mth=11">transparent</a> investigation of what went wrong.</p>
<p><strong>Disclosure of interests</strong></p>
<p>The inquiry into vaginal mesh revealed the WA Branch of Australian Medical Association had a <a href="http://www.watoday.com.au/wa-news/australian-medical-association-president-confirms-ama-was-role-in-pelvic-mesh-scandal-20170822-gy1hzj.html">financial interest</a> in a device that may have seriously affected numerous women. </p>
<p>There must be full disclosure of such interests, with meaningful sanctions where disclosure has not been made. This requires action by the TGA, professional bodies and the government.</p>
<h2>So, what about assassination by wireless pacemaker?</h2>
<p>The cybersecurity of medical devices is a matter for everyone. </p>
<p>We need the TGA to work with manufacturers, distributors and health professionals to mandate best practice. Should, for example, manufacturers and practitioners ensure that implants do not rely on default passwords that are easily <a href="https://www.fastcompany.com/3061323/brainjacking-or-how-hackers-can-remote-control-your-medical-implants">crackable</a>? What about access by emergency services?</p>
<p>There is a fundamental need to develop and enforce a national safety standard regarding all wireless implants. For that we need thoughtful policy, not just headlines.</p><img src="https://counter.theconversation.com/content/83357/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bruce Baer Arnold does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Australia’s Therapeutic Goods Administration must learn to deal with software rather than simply bits of metal and plastic.Bruce Baer Arnold, Assistant Professor, School of Law, University of CanberraLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/833622017-09-04T06:47:21Z2017-09-04T06:47:21ZThree reasons why pacemakers are vulnerable to hacking<p>The US Food and Drug Administration (FDA) <a href="https://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm573669.htm">recently recalled</a> approximately 465,000 pacemakers made by the company Abbott’s (formerly St. Jude Medical) that were vulnerable to hacking, but the situation points to an ongoing security problem.</p>
<p>The reason for the recall? The devices can be remotely “hacked” to increase activity or reduce battery life, potentially endangering patients. According <a href="http://www.abc.net.au/news/2017-08-31/pacemakers-recall-hacking-risk-australians-could-have-them/8860368">to reports</a>, a significant portion of the pacemakers are likely to be installed in Australian patients.</p>
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Read more:
<a href="https://theconversation.com/australias-car-industry-needs-cybersecurity-rules-to-deal-with-the-hacking-threat-82268">Australia's car industry needs cybersecurity rules to deal with the hacking threat</a>
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<p>Yet the qualities that make remotely-accessible human implants desirable – namely, low cost, low maintenance batteries, small size, remote access – also make securing such devices a serious challenge.</p>
<p>Three key issues hold back cyber-safety:</p>
<ol>
<li>Most embedded devices don’t have the memory or power to support proper cryptographic security, encryption or access control.</li>
<li>Doctors and patients prefer convenience and ease of access over security control.</li>
<li>Remote monitoring, an invaluable feature of embedded devices, also makes them vulnerable.</li>
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<h2>The Abbott’s situation</h2>
<p>A recall of Abbott’s pacemakers, <a href="https://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm573669.htm">per the FDA</a>, would not involve surgery. Instead, the device’s firmware could be updated with a doctor.</p>
<p>The vulnerability of the pacemaker appears to be that someone with “commercially-available equipment” could send commands to the pacemaker, changing its settings and software. The “patched” version prevents this – it only allows authorised hardware and software tools to send commands to the device. </p>
<p>Abbott’s has <a href="http://abbott.mediaroom.com/2017-08-29-Abbott-issues-new-updates-for-implanted-cardiac-devices">downplayed the</a> risks, insisting that none of the 465,000 devices have been reported as compromised. </p>
<p>But fears about cybersecurity attacks on individual medical devices are <a href="http://theconversation.com/why-has-healthcare-become-such-a-target-for-cyber-attackers-80656">nothing new</a>.</p>
<p>Medical devices are now part of the “internet of things” (IoT), where small battery-powered sensors combined with embedded and customised computers and radio communications (technologies such as Wi-Fi, Bluetooth, NFC) are finding uses in areas where cybersecurity has not previously been considered. </p>
<p>This clash of worlds brings particular challenges.</p>
<h2>1. Power versus security</h2>
<p>Most embedded medical devices don’t currently have the memory, processing power or battery life to support proper cryptographic security, encryption or access control. </p>
<p>For example, using HTTPS (a way of encrypting web traffic to prevent eavesdropping) rather than HTTP, <a href="https://www.cs.cmu.edu/%7Ednaylor/CostOfTheS.pdf">according to</a> Carnegie Mellon researchers, can increase the energy consumption of some mobile phones by up to 30% because of the loss of proxies. </p>
<p>Conventional cryptography suites (the algorithms and keys used to prove identity and keep transmissions secret) are designed for computers, and involve complex mathematical operations beyond the power of small, cheap IoT devices. </p>
<p>An emerging solution is to <a href="http://www.eetimes.com/author.asp?section_id=36&doc_id=1331566">move the cryptography</a> into dedicated hardware chips, but this raises the cost. </p>
<p>The US National Institute of Standards and Technology (NIST) <a href="https://www.nist.gov/programs-projects/lightweight-cryptography">is also developing</a> “light-weight” cryptographic suites designed for low-powered IoT devices. </p>
<h2>2. Convenience versus security</h2>
<p>Doctors and patients don’t expect to always have to log into these medical devices. The prospect of having to keep usernames, passwords and encryption keys handy and safe is contrary to how they plan to use them. </p>
<p>No one expects to have to log into their toaster or fridge, either. Fortunately the pervasiveness of smart phones, and their use as interfaces to “smart” IoT devices, is changing users’ behaviour on this front. </p>
<p>When your pacemaker fails and the ambulance arrives, however, will you really have the time (or ability) to find the device serial number and authentication details to give to the paramedics?</p>
<h2>3. Remote monitoring versus security</h2>
<p>Surgical implants present clear medical risks when they need to be removed or replaced. For this reason, remote monitoring is undoubtedly a life-saving technology for patients with these devices. </p>
<p>Patients are no longer reliant on the low battery “buzz” warning, and if the device malfunctions, its software can be smoothly updated by doctors.</p>
<p>Unfortunately, this remote control feature creates a whole new type of vulnerability. If your doctor can remotely update your software, so can others. </p>
<h2>Securing devices in the future</h2>
<p>The security of connected, embedded medical devices is a “wicked” problem, but solutions are on the horizon. </p>
<p>We can expect low-cost cryptographic hardware chips and standardised cryptographic suites designed for low-power, low-memory and low-capability devices in the future. </p>
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Read more:
<a href="https://theconversation.com/choose-better-passwords-with-the-help-of-science-82361">Choose better passwords with the help of science</a>
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<p>Perhaps we can also expect a generation who are used to logging into everything they touch, and will have ways of authenticating themselves to their devices easily and securely, but we’re not there yet. </p>
<p>In the interim, we can only assess the risks and make measured decisions about how to protect ourselves.</p><img src="https://counter.theconversation.com/content/83362/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James H. Hamlyn-Harris does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Pacemakers are Internet of Things devices for the human body, but they’re still not particularly secure.James H. Hamlyn-Harris, Senior Lecturer, Computer Science and Software Engineering, Swinburne University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/663832016-10-03T19:14:26Z2016-10-03T19:14:26ZWhy health implants should have open source code<figure><img src="https://images.theconversation.com/files/140020/original/image-20161003-7750-1o8gpve.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Open-source code can be a literal lifesaver.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/132889348@N07/20013034233/in/photolist-wuu2Qn-dnXwdA-a4gXT6-x9RxXT-9CwCuC-dnc3UK-47SBh-9CtJ5k-6Fb6Jz-64ff7i-pH6M1U-7AWDcR-fazkoJ-9fLoqt-9CtGDg-6V29dN-5yhmsT-EtLn2-8g2i2x-8cFoLy-pqA8cr-bwskff-2QxSi-9p9zyS-oDBeep-qTySso-686vNk-pqC4rj-oLaXQ3-LEQYA-7HBT3k-dJGFX-efyeGY-55dmhq-i2CQPW-7uaWcv-8MYQk8-mRuiEo-5598w2-ppqYS-3YgB7-686yEi-5Y5Q27-n4pRc-aF72ma-6gfXFF-8KGU3A-ac89Up-9c8T6e-aF72nF">Christiaan Colen/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>As medical implants become more common, sophisticated and versatile, understanding the code that runs them is vital. A pacemaker or insulin-releasing implant can be lifesaving, but they are also vulnerable not just to malicious attacks, but also to faulty code. </p>
<p>For commercial reasons, companies have been reluctant to open up their code to researchers. But with lives at stake, we need to be allowed to take a peek under the hood.</p>
<p>Over the past few years several researchers have revealed lethal vulnerabilities in the code that runs some medical implants. The late Barnaby Jack, for example, <a href="http://www.computerworld.com/article/2492453/malware-vulnerabilities/pacemaker-hack-can-deliver-deadly-830-volt-jolt.html">showed that pacemakers could be “hacked”</a> to deliver lethal electric shocks. Jay Radcliffe <a href="https://media.blackhat.com/bh-us-11/Radcliffe/BH_US_11_Radcliffe_Hacking_Medical_Devices_WP.pdf">demonstrated a way</a> of wirelessly making an implanted insulin pump deliver a lethal dose of insulin. </p>
<p>But “bugs” in the code are also an issue. Researcher Marie Moe recently discovered this first-hand, when her Implantable Cardioverter Defibrillator (ICD) <a href="https://www.wired.com/2016/03/go-ahead-hackers-break-heart/">unexpectedly went into “safe mode”</a>. This caused her heart rate to drop by half, with drastic consequences. </p>
<p>It took months for Moe to figure out what went wrong with her implant, and this was made harder because the code running in the ICD was proprietary, or closed-source. The reason? Reverse-engineering closed-source code is a crime under various laws, including the US <a href="http://copyright.gov/legislation/dmca.pdf">Digital Millennium Copyright Act 1998</a>. It is a violation of copyright, theft of intellectual property, and may be an infringement of patent law.</p>
<h2>Why researchers can’t just look at the code</h2>
<p>Beyond legal restrictions, there’s another reason why researchers can’t just look at the source code in the same way you might take apart your lawnmower. It takes a very talented programmer using expensive software to reverse-engineer code into something readable. Even then, it’s also not a very exact process. </p>
<p>To understand why, it helps to know a bit about how companies create and ship software.</p>
<p>Software starts as a set of requirements – software must do this; it must look like that; it must have these buttons. Next, the software is designed – this component is responsible for these operations, it passes data to that component, and so on. Finally, a coder writes the instructions to tell the computer how to create the components and in detail how they work. These instructions are all the source code – human-readable instructions using English-like verbs (read, write, exit) mixed with a variety of symbols which the programmer and the computer both understand. </p>
<p>Up to this point, the source code is easily understood by a human. But this isn’t the end of the process. Before software is shipped it goes through one final transformation – it is converted to machine code. It now looks like just a lot of numbers. The source code is gone, replaced by the machine code. It’s now a bit like the inside of your car stereo; it “contains no serviceable parts”. Users are not supposed to mess with the machine code. </p>
<h2>The alternative</h2>
<p>The alternative to closed-source software is open-source, which is freely available both as source code (published on websites) and as binaries or machine code. The philosophy of open-source software is that there are no secrets and no ownership. In the <a href="https://opensource.org/licenses/MIT">MIT licence</a>, which is just one kind of open-source licence, anyone can download and use the software and anyone can contribute to it, provided they retain the messages embedded in the source code by its various authors. </p>
<p>The biggest difference between open-source and closed-source is money. Developers of closed-source software get paid because they have a monopoly on their software, and software sales generate income. Open-source software developers have to find another source of income. </p>
<p>You might think that no one can make any money from open-source software, but that’s not entirely true. A lot of businesses thrive on the distribution and support of open-source software. Because open-source software is written by programmers, generally for programmers, it’s not as polished and easy to use as proprietary software. This provides a role for businesses like RedHat, IBM, Oracle, Google and Mozilla, who make the open-source software experience nicer.</p>
<h2>Closed-source or open-source?</h2>
<p>The argument has raged for decades and centres on issues of code quality and security. Open-source supporters subscribe to a “the more eyes the better” argument. If any programmer can see your code, the reasoning goes, they will discover bugs and tell you about them. The same argument is used to support the proposition that open-source software is more secure. </p>
<p>Both assertions are difficult to prove. Security vulnerabilities in <a href="http://www.openssh.com/">openSSH</a> (an open-source tool for securing connections) are constantly being found, and the <a href="https://theconversation.com/how-the-heartbleed-bug-reveals-a-flaw-in-online-security-25536">2014 Heartbleed attack</a> was based on bugs in the code that have been there for more than 12 years. On the other hand, <a href="http://arstechnica.com/security/2016/07/20-year-old-windows-bug-lets-printers-install-malware-patch-now/">a vulnerability was recently found</a> in a Windows (closed-source) automatic printer driver installer that had been in the code for almost 20 years. </p>
<p>Closed-source advocates say that their code is better because professionals (not amateurs and volunteers) are paid to read the code and find the bugs. Open-source people point out that many closed-source products (such as Windows, Microsoft Office and Adobe Acrobat) are so big that no one, paid or otherwise, understands the entire code. </p>
<p>Another argument for closed-source software is that bugs and in particular, security flaws (which do not affect the user) can remain hidden indefinitely. This is referred to as “security by obscurity”. If you can’t see the errors, then they can’t be used in cyber-attacks. The <a href="http://link.springer.com/referenceworkentry/10.1007%2F978-1-4419-5906-5_487">opposing principle</a> is that an effective security system does not rely on secrecy; only good design and a secret key.</p>
<h2>How code gets fixed</h2>
<p>When it comes to actually fixing code, the real difference between open and closed-source software is who can modify, fix or exploit the bugs when they are found. If it’s closed-source, the user has to report the bug to the author or software vendor. They then replicate the fault, open up their private code repository, find a way to fix the bug, and write a patch. Problems arise <a href="https://support.microsoft.com/en-au/help/14223/windows-xp-end-of-support">when products are no longer supported</a>, or companies extend “security by obscurity” to the point where they will ignore, <a href="http://www.smh.com.au/it-pro/security-it/backlash-after-oracle-it-security-executive-mary-ann-davidson-pens-nutty-3000word-rant-mocking-customers-for-trying-to-find-its-security-flaws-20150811-giwymy.html_">discredit</a> or <a href="http://www.scmagazineuk.com/researcher-threatened-with-prosecution-for-exposing-flaws/article/426700/3/">even prosecute</a> those who point out flaws.</p>
<p>When dealing with open-source software, on the other hand, you can report the flaw to the team of volunteers who maintain the project through the public code repository (such as GitHub, SourceForge, or GoogleCode). Then if someone is working on the project (many projects are abandoned and are not supported at all), they may fix the bug and you can then download and install the updated version. Of course there is always the possibility of a malicious programmer adding “features” like malware and backdoors to the software, although if others are working on the project they should detect such tampering. </p>
<h2>Implant manufacturers should open source software</h2>
<p>Having a open-source software run closed-source hardware is nothing new. The <a href="https://www.raspberrypi.org/">Raspberry Pi</a>, for example, uses a proprietary Broadcom graphics processing unit (GPU), the internals of which are kept secret. Broadcomm has published just enough information to allow any programmer to use the chip while maintaining its monopoly on the hardware design. In theory there is nothing stopping implant manufacturers doing the same. </p>
<p>The reason they should do it comes down to real-world experience. When someone’s pacemaker misbehaves, doctors, medical technicians and their programmers do not have the luxury of waiting for a manufacturer to release a patch or update. They need the fix immediately. That’s why manufacturers use only lightweight security on these products. When your doctor needs to access your device, they don’t have the time to mess around with cryptographic keys and authentication protocols. The most they have time for is to look up your device’s serial number and default password in your medical records. </p>
<p>While this is a security flaw, the same medical imperative argument applies to the source code. If your device goes crazy, your programmer needs to be able to find the code fast – that means open-source repository. When lives are at stake, there’s no time for secrecy. Just publish the code.</p><img src="https://counter.theconversation.com/content/66383/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James H. Hamlyn-Harris does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>When lives are at stake, there’s no time for secrecy. Just publish the code.James H. Hamlyn-Harris, Senior Lecturer, Computer Science and Software Engineering, Swinburne University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/643152016-08-23T14:58:29Z2016-08-23T14:58:29ZBrainjacking – a new cyber-security threat<figure><img src="https://images.theconversation.com/files/135131/original/image-20160823-30238-9d19tc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-424934155/stock-photo-man-face-blended-with-binary-code-digits-concept-of-hacker-coding-programming-data-protection-etc-3d-rendering.html?src=bypobwrDi2_ImSWUCrsb6Q-1-20">PHOTOCREO Michal Bednarek/Shutterstock.com</a></span></figcaption></figure><p>We live in an interconnected age where wirelessly controlled computing devices make almost every aspect of our lives easier, but they also make us vulnerable to cyber-security attacks. Today, nearly everything can be hacked, from <a href="http://arstechnica.com/security/2015/08/highway-to-hack-why-were-just-at-the-beginning-of-the-auto-hacking-era/">cars</a> to <a href="http://www.bbc.com/news/technology-28208905">lightbulbs</a>. But perhaps the most concerning threat is the one posed by implanted medical devices. Experts have <a href="http://www.bloomberg.com/news/articles/2012-02-29/mcafee-hacker-says-medtronic-insulin-pumps-vulnerable-to-attack">demonstrated</a> the ease with which security on pacemakers and insulin pumps can be breached, potentially resulting in lethal consequences.</p>
<p>In a <a href="http://www.sciencedirect.com/science/article/pii/S1878875016302728">recent paper</a> that I and several of my colleagues at Oxford Functional Neurosurgery wrote, we discussed a new frontier of security threat: brain implants. Unauthorised control of brain implants, or “brainjacking”, has been discussed in science fiction for decades but with advances in implant technology it is now starting to become possible.</p>
<h2>Deep brain stimulation</h2>
<p>The most common type of brain implant is the deep brain stimulation (DBS) system. It consists of implanted electrodes positioned deep inside the brain connected to wires running under the skin, which carry signals from an implanted stimulator. The stimulator consists of a battery, a small processor, and a wireless communication antenna that allows doctors to program it. In essence, it functions much like a cardiac pacemaker, with the main distinction being that it directly interfaces with the brain.</p>
<p>DBS is a fantastic tool for treating a wide range of disorders. It is most widely used to treat Parkinson’s disease, often with dramatic results (see video below), but it is also used to treat <a href="http://www.nhs.uk/conditions/dystonia/pages/introduction.aspx">dystonia</a> (muscle spasms), <a href="http://bit.ly/1RzP2Kt">essential tremor</a> and severe chronic pain. It is also being trialled for conditions such as depression and <a href="http://www.nhs.uk/conditions/tourette-syndrome/Pages/Introduction.aspx">Tourette’s syndrome</a>.</p>
<p>Targeting different brain regions with different stimulation parameters gives neurosurgeons increasingly precise control over the human brain, allowing them to alleviate distressing symptoms. However, this precise control of the brain, coupled with the wireless control of stimulators, also opens an opportunity for malicious attackers to go beyond the more straightforward harms that could come with controlling insulin pumps or cardiac implants, into a realm of deeply troubling attacks.</p>
<figure>
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</figure>
<h2>Remote control</h2>
<p>Examples of possible attacks include altering stimulation settings so that patients with chronic pain are caused even greater pain than they would experience without stimulation. Or a Parkinson’s patient could have their ability to move inhibited. A sophisticated attacker could potentially even induce behavioural changes such as hypersexuality or pathological gambling, or even exert a limited form of control over the patient’s behaviour by stimulating parts of the brain involved with reward learning in order to reinforce certain actions. Although these hacks would be difficult to achieve as they would require a high level of technological competence and the ability to monitor the victim, a sufficiently determined attacker could manage it.</p>
<p>There are <a href="http://www.ncbi.nlm.nih.gov/pubmed/25917056">proposed solutions</a> to making implants more resistant to cyber-attacks, but makers of these devices are in a difficult position when trying to implement security features. There’s a trade off between designing a system with perfect security and a system that is actually usable in the real world. </p>
<p>Implants are heavily constrained by physical size and battery capacity, making many designs unfeasible. These devices must be easily accessible to medical staff in an emergency, meaning that some form of “back-door” control is almost a necessity. New and exciting features, such as being able to control implants using a smartphone or over the internet, have to be balanced against the increased risk that such features can provide.</p>
<p>Brain implants are becoming more common. As they get approved for treating more diseases, become cheaper, and get more features, increasing numbers of patients will be implanted with them. This is a good thing overall but, just as a more complex and interconnected internet resulted in greater cyber-security risks, more advanced and widespread brain implants will pose tempting targets to criminals. Consider what a terrorist could do with access to a politician’s mind or how coercive blackmail would be if someone could alter how you act and think. These are scenarios that are unlikely to remain purely in the realm of science fiction for much longer.</p>
<p>It’s important to note that there’s no evidence to suggest that any of these implants has been subjected to such a cyber-attack in the real world, nor that patients with them currently implanted should be afraid. Still, this is an issue that device makers, regulators, scientists, engineers and clinicians all need to consider before they become a reality. The future of neurological implants is bright, but even a single high-profile incident could irreparably damage public confidence in the safety of these devices, so the risk of brainjacking should be taken seriously before it’s too late.</p><img src="https://counter.theconversation.com/content/64315/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laurie Pycroft receives funding from The Norman Collisson Foundation. </span></em></p>A sufficiently talented brainjacker could one day influence the behaviour of a person in worrying ways.Laurie Pycroft, PhD candidate, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/459432015-10-02T08:36:30Z2015-10-02T08:36:30ZDo brain interventions to treat disease change the essence of who we are?<figure><img src="https://images.theconversation.com/files/96977/original/image-20151001-23058-7fedmu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Brains are physical organs, but also the seat of something essential about us.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-75977104/stock-photo-teamwork-and-cooperation-in-the-sharing-and-exchange-of-ideas-and-business-know-how-represented-by.html">Heads via www.shutterstock.com.</a></span></figcaption></figure><p>These days, most of us accept that minds are dependent on brain function and wouldn’t object to the claim that “You are your brain.” After all, we’ve known for a long time that <a href="https://catalog.simonandschuster.com/TitleDetails/TitleDetails.aspx?cid=1323&isbn=9780684801582">brains control</a> how we behave, what we remember, even what we desire. But what does that mean? And is it really true?</p>
<p>Despite giving lip service to the importance of brains, in our practical life this knowledge has done little to affect how we view our world. In part, that’s probably because we’ve been largely powerless to affect the way that brains work, at least in a systematic way.</p>
<p>That’s all changing. Neuroscience has been advancing rapidly, and has <a href="https://mitpress.mit.edu/books/cognitive-neurosciences-1">begun to elucidate the circuits</a> for control of behavior, representation of mental content and so on. More dramatically, neuroscientists have now started to develop novel methods of intervening in brain function.</p>
<p>As treatments advance, interventions into brain function will dramatically illustrate the dependence of who we are on our brains – and they may put pressure on some basic beliefs and concepts that have been fundamental to how we view the world.</p>
<h2>Pacemaker for heart versus one for the brain</h2>
<p>Medicine has long intervened in the human body. We are comfortable and familiar with the reality of implants that keep the heart going at a steady and even pace. We don’t think pacemakers threaten who we are, nor that they raise deep and puzzling ethical questions about whether such interventions should be permissible. The brain, like the heart, is a bodily organ, but because of its unique function, its manipulation carries with it a host of ethical and metaphysical conundrums that challenge our intuitive and largely settled views about who and what we are.</p>
<p>The last few decades have seen a variety of novel brain interventions. Perhaps the most familiar is the systemic alteration of brain chemistry (and thus function) by a growing array of psychopharmaceuticals. However, more targeted methods of intervening exist, including direct or <a href="http://doi.org/10.1111/j.1469-7793.2000.t01-1-00633.x">transcranial electrical stimulation of cortex</a>, <a href="http://doi.org/10.3389/fnhum.2015.00303">magnetic induction of electrical activity</a>, and focal stimulation of <a href="http://www.brainfacts.org/Diseases-Disorders/Diseases-A-to-Z-from-NINDS/Deep-Brain-Stimulation-for-Parkinson-s-Disease">deep brain structures</a>.</p>
<p>Still on the horizon are even more powerful techniques not yet adapted or approved for use in humans. Transgenic manipulations that make neural tissue sensitive to light will enable the precise control of individual neurons. Powerful gene editing techniques may enable us to correct some neurodevelopmental problems in utero. And although many of these methods seem futuristic, hundreds of thousands of cases of the future are already here: over 100,000 cyborgs are already walking among us, in some sense powered by or controlled by the steady zapping of their brain circuits with electrical pulses.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/96990/original/image-20151001-23101-nb2ai1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/96990/original/image-20151001-23101-nb2ai1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/96990/original/image-20151001-23101-nb2ai1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=895&fit=crop&dpr=1 600w, https://images.theconversation.com/files/96990/original/image-20151001-23101-nb2ai1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=895&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/96990/original/image-20151001-23101-nb2ai1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=895&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/96990/original/image-20151001-23101-nb2ai1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1125&fit=crop&dpr=1 754w, https://images.theconversation.com/files/96990/original/image-20151001-23101-nb2ai1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1125&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/96990/original/image-20151001-23101-nb2ai1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1125&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Surgically inserting electrodes into a patient’s brain.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Parkinson_surgery.jpg">Thomasbg</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>This is no dystopian nightmare, nor the idea for a new zombie show. Deep brain stimulation (or <a href="https://www.nlm.nih.gov/medlineplus/ency/article/007453.htm">DBS</a>) has been a life-restoring therapeutic technique for thousands of patients with Parkinson’s disease with severely impaired motor and cognitive function, and it promises to dramatically improve the lives of people suffering from some other psychological and neurological disorders, including obsessive compulsive disorder, treatment-resistant depression, and Tourette’s syndrome.</p>
<p>DBS involves the placement of electrodes into deep brain structures. Current is administered through these electrodes by an implanted power pack, which can be remotely controlled by the subject and adjusted by physicians. In essence, DBS is like a pacemaker for the brain.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/uBh2LxTW0s0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Watch a Parkinson’s patient who has a DBS implant.</span></figcaption>
</figure>
<p>Remarkably, we don’t quite know how it works, but when effective, DBS can in seconds restore normal function to a person virtually paralyzed by a dopamine deficiency, contorted by uncontrollable tremor and muscular contraction. The transformation is nothing short of miraculous.</p>
<h2>When neuroscience answers push us toward philosophy questions</h2>
<p>In addition to its obvious clinical benefits, DBS poses some interesting problems.</p>
<p>For one thing, DBS does not always only address the troubling symptoms of the disease it aims to treat. Sometimes, stimulation results in unanticipated side-effects, altering mood, preferences, desires, emotion or cognition. In one reported case, the identifiable side effect of stimulation was a sudden and unprecedented <a href="http://dx.doi.org/10.3389/fnbeh.2014.00152">obsession with Johnny Cash’s music</a>.</p>
<p>While it may be fairly easy to write off improvements in motor control as some kind of mechanical restoration of a broken output circuit (which would be a misunderstanding of the actual function of DBS in Parkinson’s), messing with our preferences and passions seems to hit much closer to home. It calls attention to something hard to fathom and often overlooked: what we like, what we are like, who we are, in some very real sense, are dependent on the motion of matter and ebb and flow of electrical signals in our brains, just like any other physical devices.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/96995/original/image-20151001-23090-pwuke4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/96995/original/image-20151001-23090-pwuke4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/96995/original/image-20151001-23090-pwuke4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/96995/original/image-20151001-23090-pwuke4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/96995/original/image-20151001-23090-pwuke4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/96995/original/image-20151001-23090-pwuke4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/96995/original/image-20151001-23090-pwuke4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/96995/original/image-20151001-23090-pwuke4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">How much of what makes you you comes down to your physical brain?</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic.mhtml?id=278476532&src=lb-29877982">Brain image via www.shutterstock.com.</a></span>
</figcaption>
</figure>
<p>This reminder points to something we may often pay lip service to, without really coming face to face with its implications. However, the increasing availability of neurotechnologies may push us to deeper philosophical exploration of the <a href="http://doi.org/10.1098/rstb.2014.0215">truth about our brains and our selves</a>.</p>
<p>After all, if we are merely material beings whose personality can be altered and even controlled by fairly simple technologies, is there really a there there? Is there some immutable kernel of a person that is the self, or an essence that resists change? Can brain interventions can change who we are – make us into a different person or alter personal identity?</p>
<p>If someone insults you (or commits a crime) while under stimulation by DBS, should he be held responsible for what he does? Under what conditions (if any) does it make sense to say that “it wasn’t really him”? Does the answer give us insight into what matters about brain function? And if we think that brain interventions should excuse people, when and why is that so? Does that reasoning also imply that we ought to excuse all behavior due to brains, which are, after all, just physical systems operating according to natural laws? That is, does it threaten to undermine the notion of responsibility more generally? </p>
<p>These are hard questions that philosophers have been grappling with for a long time. For the most part they were relegated to the academy and the realm of thought experiments, and were largely ignored by the rest of the world. But we live today in a world of thought experiment made real, and these questions are now being raised in practical circumstances in medicine and in law. Although there is no consensus (and I do not mean to endorse what might seem to be the obvious answers to the above questions), what have previously seemed like the abstract puzzles of philosophers may soon be seen to hit closer to home.</p><img src="https://counter.theconversation.com/content/45943/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adina Roskies receives funding from Dartmouth College to pursue research on DBS.</span></em></p>New technologies bring questions that have belonged to the abstract realm of philosophers into concrete focus. Why do medical interventions in the brain feel different than those elsewhere in the body?Adina Roskies, Professor of Philosophy, Dartmouth CollegeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/442962015-07-23T20:12:56Z2015-07-23T20:12:56ZHow did it get so late so soon? Why time flies as we get older<figure><img src="https://images.theconversation.com/files/89426/original/image-20150723-22852-1rza2je.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The difference between “real” time, measured by clocks, and our own sense of time can sometimes seem enormous.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/an_solas/6722345695/in/photolist-bf2MaZ-54H6Vk-2wmtQU-9Jw4ZA-qi6o9Z-5DQKyC-nvBRCq-8Wy24N-aF3VRL-5BWVUb-9gKi6F-8dcZzA-qsbQ1g-q3dFzV-rKStBh-apoD6F-4wKyXW-EmsRz-tiUPNz-4haUGe-bEx8qg-4mDooC-uZcgZ9-njqMsS-pHcHM2-qS9iii-52H7K4-6XzhwK-nvbKHq-8kQUdS-e8b6XN-8w5ywj-7L9CKX-rqJYiZ-as8KUo-4h1HL4-daWSsk-aKHznX-6tnSaV-4zWRaS-72ERMX-6rd23p-5aiqaC-pWeGHU-sAYs4U-2saPB2-5Ss157-84Tcwu-4wXpus-cMgbim">Seán Ó Domhnaill/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><blockquote>
<p>How did it get so late so soon?<br>
It’s night before it’s afternoon.<br>
December is here before it’s June.<br>
My goodness how the time has flewn.<br>
How did it get so late so soon?<br>
<br>
Dr Seuss</p>
</blockquote>
<p>The passage of time is a puzzling thing. While few will dispute that a minute comprises 60 seconds, the perception of time can vary dramatically from person to person and from one situation to the next. Time can race, or it can drag interminably. On rare occasions, it feels as if it’s standing still.</p>
<p>The difference between “real” time, measured by clocks and calendars, and our own individual sense of time can sometimes seem enormous. This is because, in many ways, we are the architects of our sense of time. </p>
<h2>Measuring time</h2>
<p>Humans have created reliable instruments to measure time by using predictable repeating events that occur naturally, such as day turning to night or winter becoming spring. We think of these events in terms of days, weeks and years, and we use clocks and calendars to mark their passage.</p>
<p>But we also appear to possess an internal timepiece, which regulates our circadian (day/night) rhythms and allows us to register the duration of particular events. We use this “pacemaker” to compare the length of each new event with representations stored in memory. Effectively, we build up a knowledge bank of what a minute, an hour or a day feels like.</p>
<p>What typically begins as our brain’s ability to register short durations - from minutes to seconds - is transformed into an understanding of the flow of time across the lifespan. But, unfortunately, our internal pacemaker doesn’t always keep time as accurately as our external gadgets. </p>
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<img alt="" src="https://images.theconversation.com/files/88467/original/image-20150715-7554-2q1288.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/88467/original/image-20150715-7554-2q1288.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=439&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88467/original/image-20150715-7554-2q1288.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=439&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88467/original/image-20150715-7554-2q1288.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=439&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88467/original/image-20150715-7554-2q1288.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=552&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88467/original/image-20150715-7554-2q1288.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=552&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88467/original/image-20150715-7554-2q1288.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=552&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Time always seems to fly when we’re having fun.</span>
<span class="attribution"><span class="source">clock and balloons from shutterstock.com</span></span>
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<p>Individual perceptions of time are strongly influenced by our level of focus, physical state and mood. Just as “a watched pot never boils”, when we are concentrating on an event, time occasionally appears to pass more slowly than usual. This is also the case when we’re bored; time can seem to drag endlessly. </p>
<p>In other circumstances, time can appear to speed up. When our attention is divided, for instance, and we’re busy with several things at once, time seems to pass by much more swiftly. This may be because we <a href="http://www.sciencedirect.com/science/article/pii/S0001691813002515">pay less attention</a> to the flow of time when we are multi-tasking.</p>
<p>The emotional quality of an event also influences our perception of time. Negative emotional states, such as feeling sad or depressed, have the effect of making time feel as if it’s passing more slowly. <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3152725/">Fear has a particularly powerful effect</a> on time, slowing down our internal clock so that the fearful event is perceived as lasting longer. In contrast, fun and happy times seem to be over in the blink of an eye.</p>
<p>Just as time may slow or quicken depending on our current emotional state, our perception of time may also become distorted as we age. People over the age of 60 often <a href="http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198566427.001.0001/acprof-9780198566427-chapter-6">report time becoming more variable</a>. Christmas seems to come around sooner each year, and yet the days feel long and drawn out.</p>
<h2>Key factors</h2>
<p>Anomalies in time perception as we age may relate to a number of necessary cognitive processes, including how much attention we can devote to a particular task and how effectively we can divide our attention between several ongoing tasks at once. Our efficiency in these domains gradually dampens as we age and may influence the subjective perception of time. </p>
<p>Perhaps more importantly, our frame of reference for the duration of events also changes as we age. Memories we have stored throughout our lives allow us to create a personal timeline. There’s a suggestion that our perception of time may be in proportion to the length of our lifespan. Known as the “proportional theory”, this idea posits that as we age, our sense of “present” time begins to feel relatively short in comparison to our entire lifespan. </p>
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<span class="caption">Improving attention and memory can help fine-tune our internal pacemakers and bring the river of time to a slow meander.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/isadocafe/38561119/">isado/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>Proportional theory makes intuitive sense if we consider how a year in the lifespan of someone who is 75 years old may feel much quicker, for instance, in comparison to a year in the life of a ten-year-old. But it cannot fully explain our experience of present time as we can move from hour to hour and day to day independently of the past. </p>
<p>Memory may hold the key to time perception, as the clarity of our memories is believed to mould our experience of time. We mentally reflect on our past and use historic events to achieve a sense of our self existing across time.</p>
<p>As the most vividly remembered experiences tend to occur in our formative years, that is, between the ages of 15 and 25, this decade is associated with an increase in self-defining memories, known as the “<a href="http://leadserv.u-bourgogne.fr/files/publications/000876-self-centered-memories-the-reminiscence-bump-and-the-self.pdf">reminiscence bump</a>”. This memory cluster may help explain why time speeds up with age, as older people move further away from this critical period in their lives. </p>
<p>Accuracy of time perception is also disrupted in various clinical conditions. Developmental disorders, such as <a href="http://onlinelibrary.wiley.com/doi/10.1111/1469-7610.00173/full">autism and attention-deficit hyperactivity disorder</a>, for instance, are often associated with difficulties in accurately estimating time intervals. At the other end of the life spectrum, conditions such as Alzheimer’s or Parkinson’s disease are also associated with <a href="http://www.sciencedirect.com/science/article/pii/S0278262613000882">inaccuracy in timing short intervals</a>, as well as with <a href="http://www.sciencedirect.com/science/article/pii/S0010945210000262">difficulty in travelling back in subjective time </a> to remember the past. </p>
<p>Can we slow down the ever-quickening pace of life? Perhaps. Improving cognitive abilities, especially attention and memory, can help us fine-tune our internal pacemakers. And <a href="http://www.sciencedirect.com/science/article/pii/S1053810013000792">meditation and mindfulness</a> may help anchor our awareness in the here and now. Indeed, they may gradually help us to bring the fast river of time to a slow meander.</p><img src="https://counter.theconversation.com/content/44296/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Muireann Irish receives funding from the Australian Research Council (ARC DECRA) and is a previous grant recipient from Alzheimer's Australia. She is an Associate Investigator in the Australian Research Council Centre of Excellence in Cognition and its Disorders.</span></em></p><p class="fine-print"><em><span>Claire O'Callaghan receives funding from the Australian National Health and Medical Research Council.</span></em></p>While few will dispute that a minute comprises 60 seconds, the perception of time can vary dramatically from person to person and from one situation to the next. Time can race, or it can drag.Muireann Irish, Senior Research Officer, Neuroscience Research AustraliaClaire O'Callaghan, Clinical research fellow, Behavioural and Clinical Neuroscience Institute, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/290572014-07-15T13:02:00Z2014-07-15T13:02:00ZSmart pacemaker adjusts your heartbeat with your breathing<figure><img src="https://images.theconversation.com/files/53772/original/nnzj2ycx-1405332155.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Stepping up the pace.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/strolicfurlan/14024997038/sizes/l">Davide Gabino</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Pacemakers help regulate slow or skipping heartbeats through electrical currents that run via leads to the heart. Since the first artificial one was implanted <a href="http://www.nytimes.com/2002/01/18/world/arne-h-w-larsson-86-had-first-internal-pacemaker.html">into Arne Larsson</a> in 1958, <a href="http://www.bhf.org.uk/heart-health/treatment/pacemakers.aspx">modern pacemakers</a> have become a bit smaller than the size of a matchbox, weighing around 20-50g. While current pacemakers run to a set pattern, <a href="http://www.sciencedirect.com/science/article/pii/S0165027012004050">we’re working on</a> a smaller intelligent device that adjusts heartbeats to match breathing. This will improve the pumping efficiency of the heart and could, over time, help heart failure to recede. </p>
<p>The beat rate of a healthy heart is normally modulated by a respiratory cycle that causes a naturally occurring arrhythmia – something called respiratory sinus arrhythmia (RSA). This means the heart beats a little faster when you breathe in than when you breathe out. This is most prominent at birth and in trained athletes but it is lost with ageing and cardiovascular disease. RSA is normally brought about by sensory signals from the lungs and heart that tell the brain to alter heart rate, as well as cross-talk between the brain cells that specifically control heart rate and breathing.</p>
<p>RSA is highly preserved during evolution (it is still present in cartilaginous fish, amphibians, reptiles) so it must be important for life, but its functional significance in humans is still not completely understood. It has been suggested that the reason for RSA is <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3573317/">to optimise oxygen uptake</a> into the blood at the lungs. </p>
<p>Heart rate variability is known to be reduced in animals and humans with heart failure and can increase susceptibility to lethal arrhythmias and sudden cardiac death. It is therefore used as an indicator for potential problems. We wondered whether re-introducing this variability to a failing heart would have therapeutic benefit, so we set about designing a micro-stimulator capable of being triggered by inhalation. </p>
<h2>A smart way forward</h2>
<p>In invertebrates, heart pacing is performed by a small group of brain cells that generate electrical signals at precise times, called natural a central pattern generator (CPG). The simplest CPG is something called <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3090915/">a half-centred oscillator</a>, which consists of a pair or group of brain cells that compete to generate an alternating pattern of activity. The CPG technology we are developing is based on artificial brain cells made from silicon that would provide a more natural way to pace the heart dependent on the degree of physical exertion. This would allow proportional increases in heart rate based on the level of exercise.</p>
<p>Pacing using our artificial brain cells has advantages over electronics found in conventional pacemakers because our CPG will naturally synchronise the heart beat physiological signals, such as respiration and heart rate, and give appropriate timed outputs. <a href="http://www.sciencedirect.com/science/article/pii/S0165027012004050">Early trials</a> of the technology have demonstrated its efficacy of slowing down heart rate at different points of the breathing cycle in rats, and in particular we saw increases in cardiac pumping ability. Our plan now is to optimise the device and then conduct trials on human patients with heart failure.</p>
<h2>Better prognosis</h2>
<p>Worldwide, there are 22m patients with heart failure and 2m are diagnosed each year. In the UK, there are more than 750,000 patients with heart failure and despite the best medical therapy available, the prognosis remains poor. There is a significant unmet clinical need. While pacemakers are fitted for numerous heart-related diseases, our novel device could provide improved benefit to heart failure patients. </p>
<p>Current devices ensure the heart beats robustly, but metronomically. Our pacemaker would not only ensure the heart beats, but by altering the timing of the beat in a naturalistic way with breathing we believe we can improve the pumping efficiency of a failing heart. This would reverse some of the pathology within the heart and over time we hope the heart failure will recede. </p>
<p>The pacing device we’re developing, then, could provide some light at the end of the tunnel – it could lead not only to increased longevity for heart failure patients, but also greater mobility, independence and a better quality of life. </p><img src="https://counter.theconversation.com/content/29057/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Pacemakers help regulate slow or skipping heartbeats through electrical currents that run via leads to the heart. Since the first artificial one was implanted into Arne Larsson in 1958, modern pacemakers…Alain Nogaret, Lecturer, University of BathJulian Paton, Professorial Research Fellow in Physiology, University of BristolLicensed as Creative Commons – attribution, no derivatives.